Use one ml (top mark of enclosed dispenser) for each 40 liter (10 gallons) of new water. For larger doses, note that one capful (5 ml) will treat 200 liters (50 gallons). Note: The two and four liter container's cap is 10 ml. This dose removes approximately 0.6 mg/l ammonia, 3 mg/l chloramine, or 4 mg/l chlorine. May be added to aquarium directly, but better if added to new water first. If adding directly to aquarium, base dose on aquarium volume. Sulfur odor is normal. For exceptionally high chloramine concentrations, a double dose may be used safely. To detoxify nitrite in an emergency, up to five times normal dose may be used. If temperature is >86 degrees (F) and chlorine or ammonia levels are low, use a half dose. Caution. Aquarium use only. Keep away from children. Contains complexed hydrosulfite salts.